This research will investigate the site of action of adrenal glucocorticoids in regulating the response of the glycogen phosphorylase cascade to epinephrine and glucagon. Our research will also investigate the multiple forms of cyclic nucleotide phosphodiesterase. This will include 1) a study of the hormonal conditions under which these PDE forms appear in liver and 2) whether there is a relationship between the protein bound insulin and insulinase found in liver preparations of PDE and the activity of the enzyme itself.